The series opens with Jonathan Thomas Merriweather, a law student, is inadverdently summoned to a world populated by a variety of humans, anthropomorphic animals, and other fantastic and mythical creatures. Jon-Tom (as he is usually known) almost immediately meets is Mudge, the otter. Mudge helps Jon-Tom find his way to the wizard who summoned him, Clothahump, a turtle. They soon discover that when Jon-Tom sings and plays a duar (a stringed musical instrument) he has the ability to cast magic spells (i.e. he is a spellsinger, hence the title). However, he has a difficult time controlling the results of those spells, often to humorous effect.

Jon-Tom, Mudge, and Clothahump remain the three central characters of the series, which introduces a large number of other often unusual and colorful characters. The first two books are a duology while the rest are more or less standalone stories, though there is an overaching story arc spanning the series, which originally came to a resolution at the end of the sixth book. The seventh book, Son of Spellsinger, focuses on Jon-Tom and Mudge's teenage children (who hadn't been born yet in the earlier books).

The whole series was translated and published in Russia in late 1990's.

At Rainfurrest 2011, Alan Dean Foster announced that the film rights for SPELLSINGER have been optioned, and he showed conceptual drawings of Clothahump and Mudge.[citation needed]